The abstract at this link currently states: “... This report uses available data points on dust devils in Utah(3) and on Mars (including at altitudes above 16 km on Arsia Mons)(4) to question anew whether NASA failed to draw the correct conclusions. Data presented suggests that pressure there must be considerably (possibly even one or two orders of magnitude) higher than reported.”

Midoshi

Oct 26 6:45 pm

In that link David Roffman claims that the mistaken pressure of Mars surface comes from faulty pressure sensors on both the Viking and Pathfinder missions. He claims that their design was misled by the Mariner 4 estimate of 4.1-7 mbar, which he dismisses based on the mission's somewhat inaccurate estimate of a daytime surface temperature of -100°C (which, while indeed significantly lower than later assessments, is still of the correct magnitude), as well as emphasizing the fact that the probe "never got closer than 6,118 miles from Mars," as if these have a great bearing on how well the probe measured surface pressure. Roffman ignores the fact that a few years later Mariner 6 and 7 confirmed the pressure reading of Mariner 4, obtained more accurate temperature data, and got almost three times closer to the planet than Mariner 4 when they flew by. He also neglects the fact that scientists have measured the pressure of Mars' atmosphere in several other ways, such as radio occultation and spectroscopy, which give observations consistent with the results of the studies that Roffman rejects; i.e. a surface pressure of 5-10 mbar.

In short, I find nothing compelling in his arguments or conclusions.

David Roffman

Nov 10 3:07 pm

Radio occultation may work fine for getting an idea of surface pressure with 2 satellites in low orbit around Earth, but when a 1960's vintage probe over 35,000,000 miles away attempts to have its radio signals provide a detailed picture of pressures at various layers in the Martian atmosphere, with no surface means to calibrate the instrument, and TWO atmospheres for the signal to pass through (Mars AND Earth), then it becomes a very tricky proposition. Remember that we are most interested in a small depth for pressure ranges on Mars. We have seen places on Earth where people or cattle die because of carbon dioxide that vents into a valley, or over a lake, and there may be other gases at work on Mars. Yes, Mariner 6, 7 and 9 took measurements, but Mariner 9 - which got closer to Mars (about 900 mikes) saw higher pressure (and lower too) than Mariner 6. None of the pressure sensors sent to Mars were designed to measure pressure over 25 mbar. There were serious calibration problems caused by unexpected temperature ranges both outside and inside the probes. While the paper at http://davidaroffman.4t.com/photo5.html does not discuss the possibility of deliberate disinformation, the reality is that Martian weather simply does NOT fit with pressures that are near zero. Look at the data on the Tavis and Vaisala pressure transducers on the site. The companies can build great equipment, but the correct pressure sensors were not picked by NASA for the 4 missions that took surface pressure readings. At a minimum, we need a barometer on a future probe that can both see and measure higher pressures.

David Roffman

Nov 10 6:19 pm

I think the burden of proof lies not on those of us who challenge a near vacuum pressure range on Mars, but on those who can't explain what we plainly see as weather there in terms of such low pressure. Besides all the dust storms, dust devils, and obvious effects of more air, you might want to look at the picture of how a Telltale flaps around in the near vacuum there. See http://www.nasa.gov/mission_pages/phoen ... mated.html.

David Roffman

Nov 10 10:00 pm

Midoshi wrote to Servant David (about Arsia Mons):

Indeed. And what are your grounds for dismissing their suggestion that a greenhouse-thermophoretic effect might explain this? Their experiments clearly demonstrate that at ~1 mbar dust lifting is significantly more efficient.

David Roffman wrote:

The Greenhouse and Thermophoresis (GT) Effect. The article by D. Reiss et. al (2009) does suggest a greenhouse-thermophoretic (GT) effect that they believe explains ~1 mbar dust lifting at Arsia Mons. However, if anything we would expect such dust lifted at high altitude to simply drift away. The GT effect simply does not explain the structure of these events at high altitude, or why the dust rotates in columns that precisely match dust devils produced at lower altitudes.

rhw007

Nov 10 10:09 pm

rhw007 of David Roffman’s rebuff of Midoshi’s GT concerns:

I agree and with even the higher equator temps than previously thought so too about water moisture content...Mars' rule books need rewriting and sending proper weather AND a proper BIOLOGICAL component, along with broader range camera with at least 3 human normal RGB independent sensors.

Bob...

Midoshi

Nov 10 11:02 pm

David Roffman wrote:

Radio occultation may work fine for getting an idea of surface pressure with 2 satellites in low orbit around Earth, but when a 1960's vintage probe over 35,000,000 miles away attempts to have its radio signals provide a detailed picture of pressures at various layers in the martian atmosphere, with no surface means to calibrate the instrument, and TWO atmospheres for the signal to pass through (Mars AND Earth), then it becomes a very tricky proposition.

Determination of pressures in the Martian atmosphere via radio occultation was not simply done in a few attempts during the 1960s. It was also done with the Viking orbiters in the 1970s, the Pathfinder mission in the late 1990s, and as recently as the 2000s with the Mars Global Surveyor which orbited in the equivalent of "Low Mars Orbit" at an altitude of 378 km. In fact, the MGS returned daily pressure and temperature profiles for Mars by this method. It is true that there are errors due to some assumptions that must be made, such as the ideal gas law and hydrostatic equilibrium, but these are things that we do when analyzing the Earth's atmosphere as well.

David Roffman wrote:

We have seen places on Earth where people or cattle die because of carbon dioxide that vents into a valley, or over a lake, and there may be other gases at work on Mars

Midoshi responded:

Actually, I can tell you from personal experience as a professional scientist in planetary atmospherics that there cannot be other gases at work on Mars. We know very precisely from laboratory work on Earth how CO2 and H2O absorption of visible and IR light are effected by the pressure of their own species as well as foreign gases (e.g. O2, N2, Ar, etc.). By using our craft in orbit around Mars we can examine the shapes of absorption lines in thermal spectra and infer both the pressure of the absorbing species as well as any non-absorbing species. With this method there is nothing probed but the Martian atmosphere, i.e. no interference from transmission to Earth's surface. As found in the spectroscopic paper I linked to in my previous post, the results agree with the accepted surface pressure of ~10 mbar for a primarily CO2 atmosphere.

David Roffman

Nov 11, 7:58 pm

It took a lot of research to realize that there were calibration problems with Vaisala pressure sensors on Phoenix, wind calibration problems on Pathfinder, and nothing sent to the Martian surface that even had the chance to measure much above 25 (probably 18 mbar). Knowing what I do now (the next step is to check on assumptions made for flybys and orbiters. The pressure that you assume must be right, ~10 mbar, simply does NOT explain the weather that we are seeing on Mars. What you ask is a little like the Wizard telling Dorothy to, "Pay no attention to that man behind the curtain." You say that, "It is true that there are errors due to some assumptions that must be made, such as the ideal gas law and hydrostatic equilibrium, but these are things that we do when analyzing the Earth's atmosphere as well." BUT, on Earth we have in situ barometers to check on our assumptions. On Mars we have never had one sent that could work in, say 300 mbar levels. What I am arguing for (and yes, it's expensive) is to include a sensor on an upcoming mission that is designed to check on higher pressures. Tavis can do that with a 110 to 150 gram device. Maybe Vaisala could do it lighter. I know that they were not happy about getting down to to 26 grams. The raw pressure readings calculated on Phoenix differ from the actual calibrated pressure in rapidly changing temperatures (Peter A Taylor et al., 2009). While Taylor does not write about mistakes at the magnitude that I suspect, his group does not see accurate adjustments until 2010. I agree that the reference to other gases on Mars is probably off base. But moving from the shapes of absorption lines in thermal spectra to certainty about the pressure may be the problem on an alien world. It isn't supposed to snow on Mars, but Phoenix saw that it does (at night). Simple unit conversions should not be a problem for rocket scientists, but they wrecked Mars Climate Orbiter. Dust devils should not form on Arsia Mons, but they do. When confronted with weather that does not make sense, we need to re-examine EVERY assumption. Having said that, if you are an expert in this field, please provide some numbers. Given ONE satellite in low Earth orbit, precisely how close do inferred pressure readings match in situ barometers AT THE SAME EXACT TIME here? Answers in mbars or Pascals will be most appreciated. If you have massive data to transmit, please send it to DavidARoffman@Gmail.com. Thanks for your help.

David Roffman

Nov 14 8:15 pm

MIDOSHI WROTE: Indeed. And what are your grounds for dismissing their suggestion that a greenhouse-thermophoretic effect might explain this? Their experiments clearly demonstrate that at ~1 mbar dust lifting is significantly more efficient.(snip-rhw)

DAVID ROFFMAN ANSWERED: The Greenhouse and Thermophoresis (GT) Effect. The article by D. Reiss et. al (2009) does suggest a greenhouse-thermophoretic (GT) effect that they believe explains ~1 mbar dust lifting at Arsia Mons. However, if anything we would expect such dust lifted at high altitude to simply drift away. The GT effect simply does not explain the structure of these events at high altitude, or why the dust rotates in columns that precisely match dust devils produced at lower altitudes.[/quote]

BOB WROTE: I agree and with even the higher equator temps than previously thought so too about water moisture content...Mars' rule books need rewriting and sending proper weather AND a proper BIOLOGICAL component, along with broader range camera with at least 3 human normal RGB independent sensors.

Bob...

David Roffman Adds: The report by the Finish Meteorological Institute (FMI), published on 2009-02-26, states of the Vaisala pressure sensor used on Phoenix that, "We should find out how the pressure tube is mounted in the spacecraft and if there are additional filters etc." This is an enormously important statement. Four landers were supposed to measure pressure on Mars. None of them could measure anything about 25 mbar, and probably not more than 18 mbar. FMI designed the Vailsala pressure sensor. It was not given critical information about heat sources near its sensor. It was not given information about where the sensor would be positioned. It was designed to operate with ONE and only ONE dust filter between it and the silicone tube that connected it with the outside of the spacecraft. That the designer can even question whether or not there were additional filters raises grave questions about the validity of the sensor chosen by NASA for the Phoenix mission. This particular sensor, by the way, was only designed to measure between 5 and 12 mbar. If we only send sensors that can give us the answer we want, why send them at all? What we need is a total review of all data about Martian weather - right back to the Mariners. That review should be conduced by people who are NOT dependent on NASA or the U.S. Government for jobs or contracts.http://davidaroffman.4t.com/photo5.html.

jumpboy11j

Nov 14 8:28 pm

But if they could measure up to 18 millibars and obtained a measure for pressure of 7 millibars, doesn't that indicate that 7 millibars is in fact the correct pressure?

-Josh

David Roffman

Nov 14 11:09 pm

Earlier I wrote, "The report by the Finnish Meteorological Institute (FMI), published on 2009-02-26, states of the Vaisala pressure sensor used on Phoenix that, "We should find out how the pressure tube is mounted in the spacecraft and if there are additional filters etc." This is an enormously important statement.... That the designer can even question whether or not there were additional filters raises grave questions about the validity of the sensor chosen by NASA for the Phoenix mission. This particular sensor, by the way, was only designed to measure between 5 and 12 mbar....

This evening I received an e-mail from the engineer who designer the sensor. In it he claimed that, "The Barocap sensor head used in the Phoenix pressure sensor is modified for the Martian pressure range. Actually, the dynamic range of the sensor covers the whole range from vacuum to Earths atmospheric pressure (0 - 1050 hPa), but the calibration of the sensor is valid only on the Martian pressure range (5 to 12 hPa)."

If true, it may take some of the air out of my Martian balloon*, but I have requested clarification as to why his report raised the issue of additional filters. Also not yet clear, how would the limited calibration range affect the data when the transducer was subject to these higher dynamic ranges, and why the location of the instrument in Phoenix was hidden from FMI.

*NOTE: In my e-mail of Tue Nov 17, 2009 6:35 pm, the air was put back into this balloon. The dynamic pressure is not an issue, only the range of calibration is pertinent.

Midoshi

Nov 15 12:10 am

If I get some free time in the next week or so I will post a little demonstration about how we can determine Mars' pressure from absorption lines.

But one other thing I'd thought of: From observation of Mars we know that during a hemisphere's winter a portion of the atmosphere condenses and then sublimes in the spring. While it sublimes it stays at a fixed temperature of 148 K. In fact, in the southern hemisphere the summer residual CO2 cap never rises above this. Based on our knowledge of the vapor pressure of CO2 as a function of temperature, this indicates that the surface pressure of CO2 on Mars is ~ 7 mbar.

David, I respect your search for an explanation for some of the anomalous weather on Mars, but I'm afraid the evidence for your pressure hypothesis is against you.

David Roffman

Nov 15 2:56 pm

Dr. Midoshi, Thanks for your response and for your offer. I look forward to studying your demonstration, however you did not like having the GT explanation of Martian dust devils left out of discussion on the Arsia Mons article. I countered your objection by pointing out that not only did dust devils form at what is supposed to be 1 mbar, BUT THEY HAVE THE SAME STRUCTURE AS THOSE FORMING AT MORE TYPICAL MARTIAN PRESSURES. THE DUST PROBABLY SHOULD JUST BLOW AWAY. You ignored that, as you have ignored all the similarities between Martian and terrestrial dust devils. You also ignore that fact that the FMI engineer who designed the Vaisala transducer is now asking about whether somebody installed EXTRA dust filters, and he doesn't know (wasn't told) how his device was inserted in Phoenix. These FMI remarks are not trivial. I await further explanation form them. In accepting scientific data from any source, we must always look at the source. As an example, Al Gore will tell us that greenhouse effect is a real threat, while others lately are strongly challenging his assertions. Political agendas color which set of data is emphasized by the presenter. My family has long been privy to sensitive information that can not be published, but which makes me reluctant to rule out the possibility of disinformation. HOWEVER, in this study, I know that I must play with a set of rules that somewhat ties my hands behind my back. I can only discuss open source studies, NASA released data and photos, etc. That's fine. I think there is enough data to make my case under these rules, but in playing the game this way, I ask that my fellow Mars Society members examine ALL the arguments presented, and not just those that can be countered with information spoon fed to us by Uncle Sam. That's not to say that I won't work for him after my education, but he's not yet my boss. The document that I received from NASA Ames on Tavis transducers had an unclassified security rating on its abstract page, and I did not see anything classified in the body of the document. But the title page had a section blacked out. Clearly ITAR restrictions play some role in what the public can see, and if we can not see everything, we can not be certain that we have the full picture. CO2 sublimates at a higher temperature on Earth than the 148 K you cite for Mars. Pressure plays a major role in this, and I would expect temperature to stay uniform during a phase change. But are we able to continuously measure temperature at the South Pole of Mars, or are our measures there just sporadic? Are you referring to an orbiter in a polar orbit? Best regards, David A. Roffman

David Roffman

Nov 15 4:35 pm

jumpboy11j wrote:

But if they could measure up to 18 millibars and obtained a measure for pressure of 7 millibars, doesn't that indicate that 7 millibars is in fact the correct pressure?

That's a good question. From what I understand after having interviewed a Tavis rep, their sensor, if exposed to too high a pressure, would max out there, or maybe higher. It was based on a 0 to 15 volt relationship with 5 volts about the 7 mbar level, and 15 volts about 25 mbar. However, I'm still trying to learn about batteries. The Phoenix sensor was battery powered. It might be that too much constant juice (pressure) would wear down the battery and cause consistently low pressure readings. How the device is installed is also important, as I discussed with respect to the FMI not being told about heat sources or location of the transducer. Another issue relates to the narrow tube connecting the sensor with the outside. It could become clogged with dirt. Remember that Phoenix was hit with dust devils 30 times in the 151 sols. Start adding additional filters, not specified by FMA or Vaisala, but hinted at by the FMI report, and you have another complication. At least one of the three Vaisala Baracops (the RSP1) will not be used again on future missions. Its long term stability was not studied even though it had been formally qualified for Phoenix. It's best though, to defer to the full report by Peter A, Taylor et al., and that's only available in draft state for now. Finally, the temperature extremes on Phoenix, at least, were greater than those envisioned when their transducer was manufactured.

jumpboy11j

Nov 15 5:09 pm

Well, I'm neither a scientist nor engineer. In the lack of other information, though, I'm going to defer to the current scientific consensus and all of the probes that have been sent with pressure sensors.

-Josh

David Roffman

Nov 15 9:57 pm

jumpboy11j wrote:

Well, I'm neither a scientist nor engineer. In the lack of other information, though, I'm going to defer to the current scientific consensus and all of the probes that have been sent with pressure sensors.

Hi Josh, I'm not saying that they were sent with NO pressures. I'm saying that they were sent with pressure sensors that were designed for too small a pressure sensitivity range. It's like asking an adult to weigh himself on scale that was only designed to weigh small packages or stamps in a post office. If the scale only goes to one pound, how accurate will it be for a 250 pound guy? Why not look at the NASA video links that show dust devils on Mars at http://marsrovers.nasa.gov/gallery/pres ... 0819a.html? Does this look like a near vacuum? Or try viewing the telltale blowing around in the Martian wind at http://www.nasa.gov/mission_pages/phoen ... mated.html. Does it look like it's in a near vacuum? The "experts" may only pass judgment on the data given to them by NASA, but they can not control what data NASA decides to give them. In the case of the pressure sensor designed by the FMI for Phoenix, NASA would not even tell the designer where the transducer was placed in the spacecraft, or what heat sources were interfering with data. I may be entirely wrong. There is a good chance that I am wrong, but I have seen enough to know that the investigation DOES merit a closer look. Frankly, I think the emperor has no clothes. In fact, it would be interesting to hear from the folks in the Mars Society about the transitional weather on Mars should we ever terraform the place. How would that affect dust devil formation? How different would the dust devil formation rate differ then from the enormously high rate right now? Tiny Phoenix got hit with 30 dust devils in 151 Martian days. It was not a large lander that covered a huge area. The frequency of hits does not line up well with a near vacuum. Something is going on that the data provided simply does not explain. David A Roffman

David Roffman

Nov 17 6:35 pm

Earlier I wrote, This evening I received an e-mail from the engineer who designer the sensor. In it he claimed that, "The Barocap sensor head used in the Phoenix pressure sensor is modified for the Martian pressure range. Actually, the dynamic range of the sensor covers the whole range from vacuum to Earths atmospheric pressure (0 - 1050 hPa), but the calibration of the sensor is valid only on the Martian pressure range (5 to 12 hPa)."

If true, it may take some of the air out of my Martian balloon, but I have requested clarification as to why his report raised the issue of additional filters. Also not yet clear, how would the limited calibration range affect the data when the transducer was subject to these higher dynamic ranges, and why the location of the instrument in Phoenix was hidden from FMI.

Today I got a clear answer to the issue of dynamic pressure, and it put the air back in my Martian balloon. Dynamic pressure only means that the device would not break at the pressure extremes of 0 - 1050 hPa (0 to 1050 mbar). In fact, while the FMI engineer said that the calibration range was 5 to 12 hPa (mbar), the 2008 paper by Taylor et. al indicates that the Phoenix was only designed to be "capable of measuring surface pressure at a frequency of 0.5 Hz over a range of 7-11 hPa." What was NASA thinking - even at the lower limit of 7 hPa? Many of the previous estimates for Martian air pressure had been under 7 hPa! For example, Pathfinder indicated that a dust devil drove pressure down from about 6.74hPa to 6.7 hPa (which, of course, is a ridiculously small pressure drop). Why in the world would NASA want to limit pressure readings at the low end too? True, the Vaisala sensor was eventually rated to go down to 5 hPa, but it seems like NASA wanted a sensor that could only give a scripted pressure that they desired. Further, that they would not permit an anemometer on Phoenix is so serious a problem that frankly it alone merits an independent investigation. Pathfinder could not provide wind data due to calibration problems (probably due to the pressure problems that I have written about). Phoenix should have fixed the wind data deficiency, but NASA would not permit it to! We can't do real planning for Mars if we don't know what the winds are, and what pressures enforce them. DR. ZUBRIN, WAKE UP - THE AMMUNITION YOU NEED FOR YOUR FIGHT WITH NASA IS ON MY SITE (http://davidaroffman.4t.com/photo5.html). You have issued a call to battle with your e-mail about the small amount of lunar water revealed by LCROSS. But you will need more than LCROSS findings to overturn the deliberate lack of action on Mars by successive administrations. The probes we send to Mars seem to be more about PR than about learning what's really there.

jumpboy11j

Nov 18 12:13 am

One thing about phoenix- it landed at 68.4 degrees north, and 233 degrees west. Take a look at the following map:

As you can see, elevation there is about 4 km below the datum. Atmospheric pressure would be significantly higher there, especially since the air would be colder.

-Josh

David Roffman

Nov 18 10:29 am

Yes, lower landing sites will have higher pressures, but lander still needs to be ready to record lower pressures when the CO2 in the air freezes out at the south pole in winter.

I think I figured out why the Vaisala probe could not get the pressure measured right (beside the fact that the wrong pressure range sensor was selected).

The report by Kahanpää and Polkko of the FMI33 published on 2009-02-26, states of the Vaisala pressure sensor used on Phoenix that, "We should find out how the pressure tube is mounted in the spacecraft and if there are additional filters etc." This is an enormously important statement. Four landers were supposed to measure pressure on Mars. FMI designed the Vailsala pressure sensor. It was not given critical information about heat sources near its sensor. It was not given information about where the sensor would be positioned. It was designed to operate with ONE and only ONE dust filter between it and the silicone tube that connected it with the outside of the spacecraft. That the designer can even question whether or not there were additional filters raises grave about the Phoenix mission.

The issue of possible additional filters raises another possibility. There is supposed to be only one thin tube that connects the transducer to the outside atmosphere. The filter is very small. The transducer was exposed to a vacuum on the way from Earth to Mars. When the Phoenix landed, a lot of dust was raised by the retrorocket. The air pressure outside was supposed to be low, almost as low as outer space. The flow of air into the transducer therefore should not have been too fast. But, if the pressure outside was higher than expected, the rate of flow and dust into the Phoenix would be faster than planned for, with the result that dust would be rapidly sucked in just like a vacuum cleaner would suck it in. So, if the filter inside was tiny (which it was), it would quickly clog with dust. In fact, it might clog so fast that it would prevent much more air from reaching the pressure transducer. With a clogged filter, the pressure sensor would stay pegged at a low pressure reading. It would look like there were more filters present, and thus Kahanpää and Polkko would pose the question that they did about them in their report.

What Kahanpää and Polkko should have realized is that not only did NASA refuse to fund anemometer for Phoenix, but it never paid for any way to change the dust filter either! Everyone who has ever dealt with a vacuum cleaner with a clogged filter knows that it simply don't work until the filter is changed. The filter of Phoenix might well have clogged within seconds or minutes of landing. It is possible that the same applies to the Tavis transducers too.

Midoshi

Nov 19 2:59 am

Hold on, it's true I've almost got the PhD, but I'm not there yet! Midoshi is fine (for now).

David Roffman wrote:

...you did not like having the GT explanation of Martian dust devils left out of discussion on the Arsia Mons article. I countered your objection by pointing out that not only did dust devils form at what is supposed to be 1 mbar, BUT THEY HAVE THE SAME STRUCTURE AS THOSE FORMING AT MORE TYPICAL MARTIAN PRESSURES. THE DUST PROBABLY SHOULD JUST BLOW AWAY.

Midoshi wrote:

How do you know that the structure of high-altitude dust devils are the same as those for low-altitude specimens? We have observed the former by satellite alone, with a bird's eye view in single snapshots, while the latter are somewhat better understood due to ground observation from images taken by the Viking landers, Phoenix, and MERs, and local pressure readings from the former two (though your hypothesis suggests those are inaccurate). Considering how little we know about these phenomena, I find it difficult to believe one could confidently state that the two groups have identical structures. For that matter, the fact that this is an active area of research in an environmental domain we have little experience with suggests to me that we should not assume that Martian dust-devils operate on the same principles as terrestrial dust devils. It is much easier for there to be something wrong with our feeble understanding of a complex micro-scale alien weather phenomenon than to debunk all the consistent measurements of the planetary surface pressure made by many different and well-established techniques. While it is true that you look at all possibilities when anomalous behavior arises in science, it is also true that you pay more attention to the most obvious deficiencies in your knowledge.

David Roffman wrote:

You ignored that, as you have ignored all the similarities between Martian and terrestrial dust devils. You also ignore that fact that the FMI engineer who designed the Vaisala transducer is now asking about whether somebody installed EXTRA dust filters, and he doesn't know (wasn't told) how his device was inserted in Phoenix. These FMI remarks are not trivial. I await further explanation form them.

Midoshi wrote:

Well, my previous post was just introducing another point of evidence against high pressures on the Martian surface. I felt it was better to leave it at that rather than address your previous contentions as well. I will say now that while your explanation of sensor failure is not implausible, the data returned doesn't seem to indicate such. As you mentioned, the sensors in question were designed to handle terrestrial pressures but were calibrated for a lower expected range. Outside this range the data would indeed be less reliable, but the operating principle of these sensors ensures that higher pressure will still produce a higher reading. Thus, if the real pressure is above the calibrated range, the reading, while not strictly accurate, will still be above the calibrated range or jammed at its ceiling. So the fact that the measured pressures were well within the expected range and not jammed at its upper end suggests that they were indeed at the expected pressure and returned accurate data.

You suggest that the results of the surface deployed pressure sensors may have been rendered invalid by the trapping of vacuum or low pressure air by the duct being clogged with dust during landing. This seems implausible, as the craft had at least tens of seconds during descent for the sensor pressure to equilibrate with the ambient atmosphere before getting close enough to the surface for dust to be a concern. As you probably know from experience with your inner ear when flying in an airplane or driving up a mountain, it takes only a tiny fraction of a second for pressures to equalize in small spaces when given an open path. Also, measurements of pressure by surface craft have been found to vary greatly with weather (including the passing of dust devils, as hinted at before), which one would not expect with a clogged duct, as the sensor pressure would presumably be isolated. The diurnal and seasonal pressure changes observed on the surface are also consistent with observations of the same cyclic trends made from orbit, which lend credence to them being real, accurate measurements and not spurious. They are also consistent with detailed computer climate models of a thin CO2 Martian atmosphere.

David Roffman wrote:

CO2 sublimates at a higher temperature on Earth than the 148 K you cite for Mars. Pressure plays a major role in this, and I would expect temperature to stay uniform during a phase change. But are we able to continuously measure temperature at the South Pole of Mars, or are our measures there just sporadic? Are you referring to an orbiter in a polar orbit?

Midoshi wrote: Time for a little science lesson: In order to be in equilibrium, the vapor pressure of a solid or liquid must be the same as the partial pressure of its vapor in the atmosphere. If the local vapor pressure is lower than the ambient partial pressure the species will condense out of the atmosphere and if the vapor pressure is higher than ambient the liquid or solid will evaporate/sublimate. On a cool 14°C/57°F/187K day on Earth, a puddle of water will have a vapor pressure of 16 millibar. If the water vapor pressure in the surrounding air is drier than this ( i.e., relative humidity < 100% ) then the puddle will evaporate. Now, for CO2 ice the vapor pressure at 14°C is 50 bar! Since there is nowhere near that much CO2 on Earth, it will certainly evaporate. It is not until you get down to a temperature of ~ 130 K that the vapor pressure over CO2 ice is reduced to the ambient concentration in the surrounding air, about 400 microbar. So for any temperature above this, CO2 ice will sublime on Earth.

On Mars, we clearly observe the condensation of CO2 ice every year at the winter poles. It has been well documented and mapped over multiple seasons on visual wavelengths by MARCI and thermal wavelengths by THEMIS, both on MRO (this craft is indeed in a polar orbit, at an altitude of 250-320 km and a period of about 2 hours). We also know that the CO2 caps get below 148 K in the winter, but never go much above that. Instead the surface temperature remains at ~ 150 K until the ice has sublimed, which, as you rightly point out, is characteristic of a first-order phase transition. So what happens is when the local temperature attempts to rise above 148 K the vapor pressure over the CO2 ice exceeds the pressure of CO2 in the atmosphere and the ice, no longer stable, sublimes. Since we know that the vapor pressure of CO2 at 148 K is ~ 7 mbar we can infer that this is a good estimate for the ambient pressure of CO2 on the Martian surface around the poles.

David Roffman

Nov 19 8:41 pm

David Roffman wrote, you did not like having the GT explanation of Martian dust devils left out of discussion on the Arsia Mons article. I countered your objection by pointing out that not only did dust devils form at what is supposed to be 1 mbar, BUT THEY HAVE THE SAME STRUCTURE AS THOSE FORMING AT MORE TYPICAL MARTIAN PRESSURES. THE DUST PROBABLY SHOULD JUST BLOW AWAY.

Midoshi wrote, How do you know that the structure of high-altitude dust devils are the same as those for low-altitude specimens? We have observed the former by satellite alone, with a bird's eye view in single snapshots, while the latter are somewhat better understood due to ground observation from images taken by the Viking landers, Phoenix, and MERs, and local pressure readings from the former two (though your hypothesis suggests those are inaccurate). Considering how little we know about these phenomena, I find it difficult to believe one could confidently state that the two groups have identical structures.

David Roffman wrote: If it looks like a duck, walks like a duck, and quacks like a duck, it's probably a duck. 7 mbar is such a low pressure that we probably should not have dust devils there either, let alone at 1 mbar. What is the highest dust devil recorded on Earth? What is the pressure there? Whatever the pressure is, it is certainly far higher than pressure associated with any Martian dust devil. Take a look again at the distribution of dust devils on Arsia Mons) take from the D. Reiss at el. 2009 article (http://davidaroffman.4t.com/images/arsia.jpg). Yes, there a bunch above 16 km elevation, but there's another bunch at about 7 km (the lowest altitude on the figure), and of course they continue to form at every altitude down to far below the mean altitude. Are the structures of the high ones identical to the low ones? I don't know for sure, but they certainly look similar, and again, 7 mbar is still a very, very low pressure for such impressive storms.

Midoshi wrote, "While it is true that you look at all possibilities when anomalous behavior arises in science, it is also true that you pay more attention to the most obvious deficiencies in your knowledge."

David Roffman wrote: Cheap shot, but from looking at your angry face symbol, your transmission time of 2:59 AM, and the Virginia address, I'll speculate that my answers might be keeping you up late. That's probably an easier statement to contest than my other assertions. Hey don't get too pissed off at this smart assed 16-year old university sophomore. Just consider my questions as practice for the questions they throw at you in Virginia before forking a pHD to you.

Midoshi wrote, "Well, my previous post was just introducing another point of evidence against high pressures on the Martian surface. I felt it was better to leave it at that rather than address your previous contentions as well. I will say now that while your explanation of sensor failure is not implausible, the data returned doesn't seem to indicate such."

David Roffman wrote: The first part of your last sentence is the operative part here. Am I saying that NASA means Never A Straight Answer? No, in fact I've gotten some very straight answers from officials there that I'd love to print, but can't without jeopardizing careers. For here, let it just be said that not everyone at NASA is a happy camper with respect to what is released into the public domain.

Midoshi wrote, "As you mentioned, the sensors in question were designed to handle terrestrial pressures but were calibrated for a lower expected range. Outside this range the data would indeed be less reliable, but the operating principle of these sensors ensures that higher pressure will still produce a higher reading. Thus, if the real pressure is above the calibrated range, the reading, while not strictly accurate, will still be above the calibrated range or jammed at its ceiling. So the fact that the measured pressures were well within the expected range and not jammed at its upper end suggests that they were indeed at the expected pressure and returned accurate data."

David Roffman wrote: I checked on this on one of my professors here. He has significant credentials. He thought that if a sensor was exposed to much higher pressures than it was calibrated for, it would not work well or at all. We have not yet discussed the issue of dust jammed into the tiny filter that I show on my site at http://davidaroffman.4t.com/custom3_29.html.

Midoshi wrote, "You suggest that the results of the surface deployed pressure sensors may have been rendered invalid by the trapping of vacuum or low pressure air by the duct being clogged with dust during landing. This seems implausible, as the craft had at least tens of seconds during descent for the sensor pressure to equilibrate with the ambient atmosphere before getting close enough to the surface for dust to be a concern. As you probably know from experience with your inner ear when flying in an airplane or driving up a mountain, it takes only a tiny fraction of a second for pressures to equalize in small spaces when given an open path."

David Roffman wrote: I need specifics, not generalities to crank into the right equation. How many seconds? How much dust was in the air at altitude? Remember, dust devil bases are at 16 km+ on Arsia Mons. They can extend up many kilometers from there. Just how high can dust go on Mars? "When Mariner 9 arrived in November, 1971, second dust storm had been in progress several weeks. Dust cloud tops were estimated by Mariner 9 experimenters at heights of 50 to 70 kilometers (30 to 40 miles) above the surface." (http://www.jpl.nasa.gov/releases/70s/re ... _0792.html). But, of course, maybe we shouldn't trust Mariner 9 here. Those figures do not mess well with your point.

Midoshi wrote, "Also, measurements of pressure by surface craft have been found to vary greatly with weather (including the passing of dust devils, as hinted at before), which one would not expect with a clogged duct, as the sensor pressure would presumably be isolated."

David Roffman wrote: Look at how much the pressure varied! In many cases, only a fraction of a Pascal. Compare that to what you still ignore, the Utah case where a small one here (about 50-60 feet wide) was matched by a .04 inch Hg (134 Pa) drop in pressure (http://docs.lib.noaa.gov/rescue/mwr/082 ... 1-0007.pdf). You are also ignoring the fact that NASA Ames failed to reproduce dust devils in its experiment at 10 mbar without cranking up the wind speed to 70 meters per second, 156 miles per hour (http://www.nasa.gov/centers/ames/resear ... er_prt.htm). That is cheating, plain and simple. It does not line up with wind speeds seen in association with Martian dust devils, or with those nice Telltale pictures that we see at http://www.nasa.gov/mission_pages/phoen ... mated.html. You are still picking and choosing, afraid to challenge the "experts" who are beholden to selected data that NASA either wants to emphasize, or create. Yes, their data might well be correct, but it does not agree with the pictures, still and time lapse, that they release.

Midoshi wrote, "The diurnal and seasonal pressure changes observed on the surface are also consistent with observations of the same cyclic trends made from orbit, which lend credence to them being real, accurate measurements and not spurious. They are also consistent with detailed computer climate models of a thin CO2 Martian atmosphere."

David Roffman wrote: So tell me, did these sacred computer models predict the snow seen falling at night? Not from what I've read, but perhaps you or one of our readers can send a link that has the right prediction made before Phoenix found it.

Your information about vapor pressures is appreciated, and will be studied by me more. If you are busy with your course work, I am also getting ready for final exams here. If you want to speak about any of this off the record, you can contact me via my e-mail address. If you send me a phone number, I'll call you (but not at 2:59 AM). I am fully aware that I am taking on the collective wisdom of current science. This research was begun in preparation for simple, 2 to 5 page, technical paper assignment. The idea was greeted with great doubt by my professors at first, but I have been able, in just a few months, to uncover an enormous amount of information that supported my initial doubts. Have I proved my case yet? No, I still need to study how (in great detail), the remote data was obtained (and manipulated?) with the Mariners. However, if I can show that lander data is tainted, then the assumptions and pronouncements made in reference to flyby and orbiter spacecraft also become suspect.

One last question (for tonight anyway), and this one goes out not just to you, but to all those terraforming enthusiasts who visit this site. Let us assume, for argument's sake, that I am wrong, and Martian pressure really is around 7 mbar. Now let's assume that our Government decides to terraform Mars. Whether by nuking the poles, or focusing giant mirrors on them, or dumping bacteria on the planet, as page 266 of Zubrin's book, THE CASE FOR MARS discusses, what could we expect to happen to the (already very high) number of dust devils on Mars as the pressure was in the process of being elevated?

Midosh

Nov 20 7:31 pm

David Roffman wrote:

If it looks like a duck, walks like a duck, and quacks like a duck, it's probably a duck. 7 mbar is such a low pressure that we probably should not have dust devils there either, let alone at 1 mbar. What is the highest dust devil recorded on Earth? What is the pressure there? Whatever the pressure is, it is certainly far higher than pressure associated with any Martian dust devil. Take a look again at the distribution of dust devils on Arsia Mons) take from the D. Reiss at el. 2009 article (http://davidaroffman.4t.com/images/arsia.jpg). Yes, there a bunch above 16 km elevation, but there's another bunch at about 7 km (the lowest altitude on the figure), and of course they continue to form at every altitude down to far below the mean altitude. Are the structures of the high ones identical to the low ones? I don't know for sure, but they certainly look similar, and again, 7 mbar is still a very, very low pressure for such impressive storms.

Midoshi Wrote:

Mm, I'm not buying it. I'll use an analogy here. We see clouds on Venus, Mars, Jupiter, Titan, and other bodies with an atmosphere. Since virtually all the clouds on Earth are made of H2O, should we assume that all other planetary clouds are all H2O? Of course not. There are many other compounds that can form clouds in the solar system, like CO2, H2SO4, NH3, and CH4, and they all form at different temperatures. On Earth we see dust devils and storms when soil is dry and winds are strong enough to saltate surface particles. It seems to me that to do a proper analysis you cannot ignore the possibility that other alien physics may be acting in concert on Mars. Electrostatic levitation of grains, a G-T effect, and the observed wind speeds together may be able to satisfactorily explain the dust phenomena seen. The problem is that further research needs to be done. You're more than welcome to make an a priori assumption that Martian dust phenomena are identical with those of Earth and then make a case for debunking measurements of Martian atmospheric pressure. But be aware that just as your case is built upon attacking the assumed surface pressure, the weak point of your own argument is your assumption about the physics governing dust devil behavior.

Midoshi wrote:

While it is true that you look at all possibilities when anomalous behavior arises in science, it is also true that you pay more attention to the most obvious deficiencies in your knowledge.

Midoshi wrote:

As you mentioned, the sensors in question were designed to handle terrestrial pressures but were calibrated for a lower expected range. Outside this range the data would indeed be less reliable, but the operating principle of these sensors ensures that higher pressure will still produce a higher reading. Thus, if the real pressure is above the calibrated range, the reading, while not strictly accurate, will still be above the calibrated range or jammed at its ceiling. So the fact that the measured pressures were well within the expected range and not jammed at its upper end suggests that they were indeed at the expected pressure and returned accurate data.

Midoshi wrote:

You suggest that the results of the surface deployed pressure sensors may have been rendered invalid by the trapping of vacuum or low pressure air by the duct being clogged with dust during landing. This seems implausible, as the craft had at least tens of seconds during descent for the sensor pressure to equilibrate with the ambient atmosphere before getting close enough to the surface for dust to be a concern. As you probably know from experience with your inner ear when flying in an airplane or driving up a mountain, it takes only a tiny fraction of a second for pressures to equalize in small spaces when given an open path."

David Roffman wrote:

I need specifics, not generalities to crank into the right equation. How many seconds?

Midoshi wrote:

Then specifics ye shall have.That analysis is for gas leaking out of a pressurized chamber, but it should also be fairly valid for gas leaking into an unpressurized one. I'll leave plugging in numbers to you (remember Mars' atmosphere is a different composition and temperature ). Based on this transcript and timeline the craft was at ~ 1 km ~ 40 seconds before landing, well within a scale height of the surface (pressure should be within ~90% of surface). About 20 seconds later, the constant velocity phase began at 40-60 m, with Phoenix gently descending to the surface over the next 20 seconds or so. Given these heights and speeds of descent, surface dust kicked up by the thrusters should not have clogged the sensor before it reached pressure equilibrium. But it seems you have changed your hypothesis to question whether ambient dust in the atmosphere high above the surface could have caused clogging.

David Roffman wrote:

How much dust was in the air at altitude? Remember, dust devil bases are at 16 km+ on Arsia Mons. They can extend up many kilometers from there. Just how high can dust go on Mars? "When Mariner 9 arrived in November, 1971, second dust storm had been in progress several weeks. Dust cloud tops were estimated by Mariner 9 experimenters at heights of 50 to 70 kilometers (30 to 40 miles) above the surface." (http://www.jpl.nasa.gov/releases/70s/re ... _0792.html). But, of course, maybe we shouldn't trust Mariner 9 here. Those figures do not mess well with your point.

Midoshi wrote:

Those Mariner 9 readings are consistent with more recent observations, that is, that there is dust present at high altitudes on Mars (70-80 km during the 2001 global dust storm). But unless a powerful storm is occurring (not the case during Phoenix's landing) the dust more than a dozen meters above the surface is a different population than the coarse stuff near the ground. It is very fine, on the order of a few microns, and of roughly constant loading within the boundary layer, up to ~ 4 km at the Phoenix site based on the craft's own lidar measurements. The opacity corresponds to a density of about 10-100 million particles per cubic meter under moderately dusty conditions. To form a monolayer thick "clog" of dust particles in a 2 mm wide tube (I'm just estimating here) would require 1 million of these particles. So the sensor would have needed to "inhale" 10-100 liters of air to get anything that could remotely be called a clog. That's not reasonable. With your vacuum cleaner analogy the volume of air processed is not limited to the size of the device and so can build up large amounts of material, but in this case a very small amount of dust could have been drawn into the sensor.

Midoshi

Nov 21 1:04 am

David Roffman wrote:

Midoshi wrote, "Also, measurements of pressure by surface craft have been found to vary greatly with weather (including the passing of dust devils, as hinted at before), which one would not expect with a clogged duct, as the sensor pressure would presumably be isolated."

Look at how much the pressure varied! In many cases, only a fraction of a Pascal. Compare that to what you still ignore, the Utah case where a small one here (about 50-60 feet wide) was matched by a .04 inch Hg (134 Pa) drop in pressure (http://docs.lib.noaa.gov/rescue/mwr/082 ... 1-0007.pdf). You are also ignoring the fact that NASA Ames failed to reproduce dust devils in its experiment at 10 mbar without cranking up the wind speed to 70 meters per second, 156 miles per hour (http://www.nasa.gov/centers/ames/resear ... er_prt.htm). That is cheating, plain and simple. It does not line up with wind speeds seen in association with Martian dust devils, or with those nice Telltale pictures that we see at http://www.nasa.gov/mission_pages/phoen ... mated.html. You are still picking and choosing, afraid to challenge the "experts" who are beholden to selected data that NASA either wants to emphasize, or create. Yes, their data might well be correct, but it does not agree with the pictures, still and time lapse, that they release.

Yes, such a small drop is indeed puzzling if you are working under the assumption that Mars has a thick atmosphere. But for a vortex that can lift dust in a ~ 7 mbar atmosphere at 3.8g, one would expect a core drop of 2 or 3 Pa. And unless the vortex passes directly over you, you will not see the full drop. Also, if the vortex has a high lateral velocity it may pass by too quickly for the craft's barometer to accurately measure it (sample time on Phoenix was every few seconds), thus missing the drop's peak. If anything I'd say the Utah account is proof that Mars atmosphere is indeed thin, since as you say a larger response would otherwise be expected. From the details of the encounter such a fluctuation should have driven even a damaged, weakly responsive pressure sensor haywire.

I am not sure why you keep going on about that NASA Ames article which mentions that their vortex simulator is capable of 70 m/s wind speeds. Based on what I have seen of their published research, they typically operate it at much lower velocities. Based on the results in this paper they find there are additional forces on small particles (< 60 microns) and at low pressures ( < 65 mbar) that increase the lifting power of vortices several times beyond what would be expected from a regular boundary layer entrainment models. Based on their data, they suggest that 20-30 m/s wind tangential winds could lift micron sized particles at a pressure of 10 mbar. But this is at Earth gravity, and so the required speeds on Mars will be even lower.

David Roffman wrote:

Quote:

Midoshi wrote, "The diurnal and seasonal pressure changes observed on the surface are also consistent with observations of the same cyclic trends made from orbit, which lend credence to them being real, accurate measurements and not spurious. They are also consistent with detailed computer climate models of a thin CO2 Martian atmosphere."

So tell me, did these sacred computer models predict the snow seen falling at night?

Midishi wrote:

Yes, they did. In fact, they identify it as being a key process that helps models agree better with observation of water vapor and dust levels. And there have been previous atmospheric observations indicating snow on Mars.

By the way, the seasonal pressure trends (Viking data) on Mars measured by Viking and Phoenix were on the order of hundreds of Pa. So the sensors were certainly capable of such a large response. Such changes are due to CO2 migrating between the poles between polar winters, and as I mentioned before the observation from the surface and orbit are consistent with climate models with respect to the magnitude and timing of the fluctuations.

Midoshi

Nov 21 2:19 pm

David Roffman wrote:

One last question (for tonight anyway), and this one goes out not just to you, but to all those terraforming enthusiasts who visit this site. Let us assume, for argument's sake, that I am wrong, and Martian pressure really is around 7 mbar. Now let's assume that our Government decides to terraform Mars. Whether by nuking the poles, or focusing giant mirrors on them, or dumping bacteria on the planet, as page 266 of Zubrin's book, THE CASE FOR MARS discusses, what could we expect to happen to the (already very high) number of dust devils on Mars as the pressure was in the process of being elevated?

Midoshi wrote:

That's a pretty complex question. I suspect that a high resolution global climate model would be needed to really answer it. What I can say is that thickening Mars' atmosphere ought to have a mellowing effect on the weather in the long term. A thicker blanket of air has a higher heat capacity, reducing the diurnal temperature extremes. With more of the surface energy coming from reflected IR radiation, ices on the surface will be closer in temperature to dark soils (ices tend to reflect visible light but absorb IR with near 100% efficiency). This will choke off some of the strongest winds on Mars, which form due to temperature differences between the polar caps and surrounding areas. Finally, a denser atmosphere means air doesn't have to be transported so quickly between regions with different temperatures to satisfy the kinetics of disequilibrium, so wind speeds might be expected to go down. What exactly this would imply for dust devils, I'm not sure. If thickening the atmosphere several fold only halves the weather forcing gradients, then you could probably expect more and/or stronger dust devils. If thickening the atmosphere just a bit causes a disproportionately large mellowing effect, then less and/or weaker ones. But this is just educated guessing.

David Roffman

Nov 21 10:49 pm

Midoshi wrote

Quote:

On a cool 14°C/57°F/187K (typo - 287 K) day on Earth, a puddle of water will have a vapor pressure of 16 millibar. If the water vapor pressure in the surrounding air is drier than this ( i.e., relative humidity < 100% ) then the puddle will evaporate. Now, for CO2 ice the vapor pressure at 14°C is 50 bar! Since there is nowhere near that much CO2 on Earth, it will certainly evaporate. It is not until you get down to a temperature of ~ 130 K that the vapor pressure over CO2 ice is reduced to the ambient concentration in the surrounding air, about 400 microbar. So for any temperature above this, CO2 ice will sublime on Earth. On Mars, we clearly observe the condensation of CO2 ice every year at the winter poles. It has been well documented and mapped over multiple seasons on visual wavelengths by MARCI and thermal wavelengths by THEMIS, both on MRO (this craft is indeed in a polar orbit, at an altitude of 250-320 km and a period of about 2 hours). We also know that the CO2 caps get below 148 K in the winter, but never go much above that. Instead the surface temperature remains at ~ 150 K until the ice has sublimed, which, as you rightly point out, is characteristic of a first-order phase transition. So what happens is when the local temperature attempts to rise above 148 K the vapor pressure over the CO2 ice exceeds the pressure of CO2 in the atmosphere and the ice, no longer stable, sublimes. Since we know that the vapor pressure of CO2 at 148 K is ~ 7 mbar we can infer that this is a good estimate for the ambient pressure of CO2 on the Martian surface around the poles.

David Roffman wrote: I just found a site (http://www.daviddarling.info/encycloped ... poles.html) that claims there is actually only a small amount of dry ice at the Martian poles, about 1 meter thick at the north polar cap, and 8 meters at the southern one in winter. That's not too much, and if correct, seems to be a good bit less than previous models. Is this correct? The article argues that only at the southern pole does the CO2 not disappear totally.

I'm trying to correlate the altitude and latitude of the poles with affects on pressure. It looks like air pressure at our south pole is only on the order of 670 to 680 mbar (http://astro.uchicago.edu/cara/southpol ... ther2.html), but its high there (2,838 meters which = 9,311 feet). A chart at http://www.sensorsone.co.uk/altitude-pr ... rsion.html indicates that the pressure at 9,000 feet should be about 724 mbar, and at 10,000 feet should be 696 mbar. So maybe 9,311 feet would equal a pressure of about 721 mbar here. The 670 to 680 mbar at the south pole here might be due to the fact that while the troposphere is about 11 miles thick at the equator, it's only about 5 miles thick at the poles (spin of the Earth + colder temps). Mars rotates in about the same rate as Earth, but of course the radius of the planet is about half Earth's. So perhaps when we speak about the pressure at the Martian south pole, where the atmosphere is probably not as thick as at lower latitudes, the 7 mbar figures derived from there might not be representative of what we should see at lower latitudes everywhere. In the northern hemisphere, all the dry ice is gone in the summer, and perhaps with it, the limit on air pressure.

David Roffman

Nov 22 12:15 am

David Roffman wrote: If it looks like a duck, walks like a duck, and quacks like a duck, it's probably a duck. 7 mbar is such a low pressure that we probably should not have dust devils there either, let alone at 1 mbar. What is the highest dust devil recorded on Earth? What is the pressure there? Whatever the pressure is, it is certainly far higher than pressure associated with any Martian dust devil. Take a look again at the distribution of dust devils on Arsia Mons) take from the D. Reiss at el. 2009 article (http://davidaroffman.4t.com/images/arsia.jpg). Yes, there a bunch above 16 km elevation, but there's another bunch at about 7 km (the lowest altitude on the figure), and of course they continue to form at every altitude down to far below the mean altitude. Are the structures of the high ones identical to the low ones? I don't know for sure, but they certainly look similar, and again, 7 mbar is still a very, very low pressure for such impressive storms.

Midoshi wrote: Mm, I'm not buying it. I'll use an analogy here. We see clouds on Venus, Mars, Jupiter, Titan, and other bodies with an atmosphere. Since virtually all the clouds on Earth are made of H2O, should we assume that all other planetary clouds are all H2O? Of course not. There are many other compounds that can form clouds in the solar system, like CO2, H2SO4, NH3, and CH4, and they all form at different temperatures. On Earth we see dust devils and storms when soil is dry and winds are strong enough to saltate surface particles. It seems to me that to do a proper analysis you cannot ignore the possibility that other alien physics may be acting in concert on Mars. Electrostatic levitation of grains, a G-T effect, and the observed wind speeds together may be able to satisfactorily explain the dust phenomena seen. The problem is that further research needs to be done. You're more than welcome to make an a priori assumption that Martian dust phenomena are identical with those of Earth and then make a case for debunking measurements of Martian atmospheric pressure. But be aware that just as your case is built upon attacking the assumed surface pressure, the weak point of your own argument is your assumption about the physics governing dust devil behavior.

David Roffman responds: Your analogy of clouds may look like a duck, but it doesn't walk like or talk like a duck, i.e.. the general consensus of all seems to be that Martian dust devils are very similar to terrestrial ones in many, many areas - apparently in all areas except for absolute and relative pressure excursions. And then your stuck trying to move to the GT effect at high altitude while ignoring the fact that they seem to form at every other altitude there.

Midoshi wrote, "As you mentioned, the sensors in question were designed to handle terrestrial pressures but were calibrated for a lower expected range. Outside this range the data would indeed be less reliable, but the operating principle of these sensors ensures that higher pressure will still produce a higher reading. Thus, if the real pressure is above the calibrated range, the reading, while not strictly accurate, will still be above the calibrated range or jammed at its ceiling. So the fact that the measured pressures were well within the expected range and not jammed at its upper end."

David Roffman responds: Frankly, I looked the Phoenix readings and how they steadily declined from 8.5 to 7.4 mbar over the probes lifetime. It was such a straight line, that it looked more like the graph of steadily dying battery. (see Figure 2 to http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1732.pdf). I think the pressure sensor was battery operated, but I don't know if this in any way relates to the graph. Yes, I see that the graph agrees with the GCM model, but I don't know the logic behind that model yet, or whether someone is just working overtime to make the probe look good.

Midoshi wrote: You suggest that the results of the surface deployed pressure sensors may have been rendered invalid by the trapping of vacuum or low pressure air by the duct being clogged with dust during landing. This seems implausible, as the craft had at least tens of seconds during descent for the sensor pressure to equilibrate with the ambient atmosphere before getting close enough to the surface for dust to be a concern. As you probably know from experience with your inner ear when flying in an airplane or driving up a mountain, it takes only a tiny fraction of a second for pressures to equalize in small spaces when given an open path."

Midoshi wrote But it seems you have changed your hypothesis to question whether ambient dust in the atmosphere high above the surface could have caused clogging.

David Roffman Responds: When you led me to Mariner 9, I discovered just how high dust clouds on Mars can go (40 miles). But, remember that dust clouds are not the only way dust gets into the Martian atmosphere. The main way seems to be by dust devils. Just think about Phoenix, in its tiny little area occupied, got hit with 30 of them in 151 sols! How many others were nearby undetected? How many might have recently put dust into the air as Phoenix descended? Dust devils are not at all a rare feature there, they are apparently major factors in daily weather on the planet. But, your figures are appreciated, and as time permits, will be worked into my calculations.

David Roffman

Nov 22 11:11 am

Midoshi wrote:

David Roffman wrote:

Quote:

Midoshi wrote, "Also, measurements of pressure by surface craft have been found to vary greatly with weather (including the passing of dust devils, as hinted at before), which one would not expect with a clogged duct, as the sensor pressure would presumably be isolated."

Look at how much the pressure varied! In many cases, only a fraction of a Pascal. Compare that to what you still ignore, the Utah case where a small one here (about 50-60 feet wide) was matched by a .04 inch Hg (134 Pa) drop in pressure (http://docs.lib.noaa.gov/rescue/mwr/082 ... 1-0007.pdf). You are also ignoring the fact that NASA Ames failed to reproduce dust devils in its experiment at 10 mbar without cranking up the wind speed to 70 meters per second, 156 miles per hour (http://www.nasa.gov/centers/ames/resear ... er_prt.htm). That is cheating, plain and simple. It does not line up with wind speeds seen in association with Martian dust devils, or with those nice Telltale pictures that we see at http://www.nasa.gov/mission_pages/phoen ... mated.html. You are still picking and choosing, afraid to challenge the "experts" who are beholden to selected data that NASA either wants to emphasize, or create. Yes, their data might well be correct, but it does not agree with the pictures, still and time lapse, that they release.

Midoshi wrote, Yes, such a small drop is indeed puzzling if you are working under the assumption that Mars has a thick atmosphere. But for a vortex that can lift dust in a ~ 7 mbar atmosphere at 3.8g, one would expect a core drop of 2 or 3 Pa. And unless the vortex passes directly over you, you will not see the full drop. Also, if the vortex has a high lateral velocity it may pass by too quickly for the craft's barometer to accurately measure it (sample time on Phoenix was every few seconds), thus missing the drop's peak. If anything I'd say the Utah account is proof that Mars atmosphere is indeed thin, since as you say a larger response would otherwise be expected. From the details of the encounter such a fluctuation should have driven even a damaged, weakly responsive pressure sensor haywire.

David Roffman I was not at all working under the assumption that Mars had a thick atmosphere when I first began to research this issue, though I suspected it did. The Utah case demonstrates just how large pressure drops are here even with small dust devils that have a lot of air to work with. 134 Pa in a small event here, vs. often about 0.5 Pa on Mars. If anything, given that we are asked to believe about Mars that the air is so thin there as to be a near vacuum, it would be logical to assume the dust devils on Mars would at least involve a larger percent or relative pressure drop than seen on Earth, but, no, they don't. That leaves us with less force for a pressure differential to generate them or explain them there - unless we go to the higher ambient pressures than NASA will admit to. Or do you want to move the GT effect down from the summits of Arsia Mons to every other lower altitude? And with respect to Arsia Mons, let's go the other way up to the top of Olympus Mons. If the GT effect explains things at 16 km, we should also see dust devils on top of Olympus Mons at 27 km. Have you seen any there? If not, the implication may be that there is enough pressure and pressure differential to generate them at 16 km, but not 27 km. I think the absence of them on Olympus Mons would be a strong indication that the GT effect is incorrect.

David Roffman

Nov 22 12:35

Midoshi wrote, "I am not sure why you keep going on about that NASA Ames article which mentions that their vortex simulator is capable of 70 m/s wind speeds. Based on what I have seen of their published research, they typically operate it at much lower velocities. Based on the results in this paper they find there are additional forces on small particles (< 60 microns) and at low pressures ( < 65 mbar) that increase the lifting power of vortices several times beyond what would be expected from a regular boundary layer entrainment models. Based on their data, they suggest that 20-30 m/s wind tangential winds could lift micron sized particles at a pressure of 10 mbar. But this is at Earth gravity, and so the required speeds on Mars will be even lower."

David Roffman wrote: It's a big deal because the simulated Martian atmosphere in the wind tunnel is so tenuous that a fan would have to spin at too high a speed to blow thin wind through the test section (I think they may have modified their words since I brought attention to them). The current quote at http://www.nasa.gov/centers/ames/resear ... er_prt.htm is

The simulated martian atmosphere in the wind tunnel is so tenuous that a fan would have to spin at too high a speed to blow thin wind through the test section. The high-pressure air draws thin air through the tunnel like a vacuum cleaner sucks air. Scientists also compare this process to a person sucking water through a straw. The resulting simulated Mars wind moves at about 230 feet (70 meters) per second.

M.D. Elohoj et al (2009) http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1558.pdf state that the typical vortex has wind speeds of 6 meters per second. So if NASA Ames can't generate them with a fan spinning at any speed in 10 mbar, and if they have to resort to tricks with winds at 70 meters per second, they are cheating and giving us junk results. The questions, are we going to bow to Big Brother and say, "Yes, of course, there is no significance to this?" Or are we going to wake up and say, "Wait a minute, something stinks here?" Until the Administration was around to push so hard for socialized medicine, the wisdom was that a woman should have mammogram starting at age 40. Then someone took a look at the cost overruns of the program, and changed it to 50. The Administration said the economic recovery was working, but the real figures show more unemployment and continued decline in home prices. The Administration gave figures for job creation in congressional districts that simply don't exist (http://abcnews.go.com/Politics/jobs-sav ... id=9097853)! If the Government can lie and distort information on Health Care and the Economy, it can do so on sensitive data from Mars too. But is there any reason to do so? Unless just an advertisement for mental health care, maybe you should take a look at what Buzz Aldrin had slip through on a C-SPAN TV appearance this summer. The regular "News" media did a great job in covering it up or ignoring it, but his words are still out there at http://www.youtube.com/watch?v=bDIXvpjnRws. When you get to the point (about 39 seconds into the video) where he makes his startling assertion, note that somebody pulls his notes from before him. Our family has personal knowledge of events leading up to his C-SPAN words. There is ample reason to put everything that NASA asserts under the microscope when it does not mesh well with common sense. You write off the explanation in terms of alien physics. But there's more than one way to interpret the meeting of those two words. Just ask Buzz or even Edgar Mitchell (http://www.youtube.com/watch?v=RhNdxdve ... re=related). The truth is out there, but yes, it is proper to focus just on the meteorology here rather than policy or sanity issues. So the focus will just be on physics rather than alien physics. Right now I'm trying to line up what experiments can be done at ERAU to support my contentions about air pressure. I have some ideas. Of course, what can be done is related to equipment available. Suggestions are always welcome.

David A Roffman

Nov 26 2:05 pm

The report by S.M. Nelli et al. (2009) shows a steady pressure drop over the Phoenix mission from about 8.5 mbar at the start in late Martian spring to 7.4 mbar at the end at mid Martian summer, this despite a temperature range from beginning to end that is not great. The report sees this as in line with the NASA Ames General Circulation Model (GCM), but the pressure drop when graphed is so steady as to look more like a slowly dying battery. In fact, Phoenix had battery problems. From JPL on October 29 2008 ( (http://www.jpl.nasa.gov/news/news.cfm?release=2008-200):

Quote:

NASA'S Phoenix Mars Lander entered safe mode late yesterday in response to a low-power fault brought on by deteriorating weather conditions. While engineers anticipated that a fault could occur due to the diminishing power supply, the lander also unexpectedly switched to the "B" side of its redundant electronics and shut down one of its two batteries.

During safe mode, the lander stops non-critical activities and awaits further instructions from the mission team. Within hours of receiving information of the safing event, mission engineers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and at Lockheed Martin in Denver, were able to send commands to restart battery charging. It is not likely that any energy was lost.

Weather conditions at the landing site in the north polar region of Mars have deteriorated in recent days, with overnight temperatures falling to -141F (-96C), and daytime temperatures only as high as -50F (-45C), the lowest temperatures experienced so far in the mission. A mild dust storm blowing through the area, along with water-ice clouds, further complicated the situation by reducing the amount of sunlight reaching the lander's solar arrays, thereby reducing the amount of power it could generate. Low temperatures caused the lander's battery heaters to turn on Tuesday for the first time, creating another drain on precious power supplies.

The Nelli (2009) article and graphs in particular raise the question of how accurate the GCM can be, especially given the sparsity of in situ measurements before on Mars. Phoenix had no anemometer, the Finnish Meteorological Institute that designed the Vaisala pressure sensor for Phoenix has asked whether NASA put in extra filters without telling them, and PathFinder never got its anemometer calibrated. How much can we trust modes like GCM? Before issuing a knee-jerk response, remember that data about global warming on Earth was recently shown to be deliberately corrupted (http://www.examiner.com/x-30215-LA-Cons ... limategate).

The pressure changes on Mars for each site examined are alleged by NASA to be very small, but common sense would seem to dictate more variation in pressure for each site as fronts and storms pass, not a bleed off in pressure that is damn near a straight diagonal slope down. The graph in question is reproduced on my own site athttp://davidaroffman.4t.com/whats_new_3.html. I'm still working on my commentary about it there, but would like to hear from experts out here on this issue.

David Roffman

Nov 26, 6:56 pm

jumpboy11j wrote:

One thing about phoenix- it landed at 68.4 degrees north, and 233 degrees west. Take a look at the following map: (Google Mars map previously sent)

As you can see, elevation there is about 4 km below the datum. Atmospheric pressure would be significantly higher there, especially since the air would be colder.

David Roffman responds: I looked at your Google Mars based MOLA map of Mars. While your point about atmospheric pressure being higher at lower altitudes is correct, the map had several errors with respect to how the landers were plotted. These errors touched on how to specify longitude, and in the case of Mars Pathfinder, the altitude at the landing site. I have appropriate corrections on my site at http://davidaroffman.4t.com/whats_new_4.html. But thanks for sending me the map, it was a great way to start looking at elevation issues,

David Roffman

Dec 01, 10:46 pm

David Roffman wrote:

Quote:

So tell me, did these sacred computer models predict the snow seen falling at night?

Midoshi wrote,

Quote:

Yes, they did [rl=http://mh-gps-p1.caltech.edu/uploads/File/People/mir/Richardson_JGR10.1029_2001JE001804.pdf]. In fact, they identify it as being a key process that helps models agree better with observation of water vapor and dust levels. And there have been previous atmospheric observations indicating snow on Mars.

David Roffman responded: OK, I looked at the Richardson article. My comment is that while it is true that Richardson et al (2002) discussed snow on Mars before it was seen by Phoenix, it is also true that they declared that in order to get a good fit to all other data, cloud ice particle sizes about an order of magnitude too large (that is, greater than observations allow) must be used. They state that “significant work remains to be done assessing the quality of GCM (General Circulation Model) predictions of Martian circulation vigor and resultant tracer transport.” Richardson et al concede the need to bump up ice particle size to levels that are “unrealistically large,” but they were stuck with legacy pressure data. Obviously, larger ice particle size would be easier to understand if there was a greater atmospheric density (and pressure) than previously canonized by NASA.

Rockinright

Dec 2, 12:14 am

Weird stuff.

Questions:

1. What benefit would NASA get from lying? Being dishonest about a healthcare plan has it's reasons, but, unless the atmosphere is so thick that it would give them less excuse not to do a manned mission, I can't think of any reason why the government would lie about this.

2. Just how "thick" are we talking? 10mb? 100mb? 500mb?

David Roffman

Dec 02, 2009 12:18 pm

rockinright wrote:

Weird stuff.

Questions:

1. What benefit would NASA get from lying? Being dishonest about a healthcare plan has it's reasons, but, unless the atmosphere is so thick that it would give them less excuse not to do a manned mission, I can't think of any reason why the government would lie about this.

2. Just how "thick" are we talking? 10mb? 100mb? 500mb?

David Roffman responds:

We have just learned that global warming data for Earth was being faked (Climate Gate). On my web site my goal is just to lay out the meteorological case for higher pressure. Originally I had guessed one to two orders of magnitude higher. That translates to anywhere from 75 to 750 mbar. I have not yet done the math to nail down the right figure, though I'd like to next semester. It is probable that I will take a one on one course with a professor who will help me acquire the skills required to do so, but for now I'm just a 16-year old university sophomore taking calculus 3 without a single meteorology course under my belt.

Answering the question of why the lie is far trickier than discovering that the data makes no sense. Indeed, there is not necessarily a lie. There is only direct evidence that there were mistakes and mission design flaws, which in large part could have been caused by budget restrictions. Perhaps NASA could not afford to put an anemometer on Phoenix, it could not afford to put two pressure range sensors on landers (with one capable of accurately measuring higher pressures than the old Mariners surmised), as it could not afford to double check calculations by Lockheed Martin when it used imperial units (pounds-seconds) instead of the metric system and thus sent Mars Climate Orbiter crashing in Mars.

The question of why the lie only truly comes into focus if it can be proven that the problem is due to disinformation rather than incompetence. I'm not there yet, but this much I know. I know that two astronauts who landed on the moon, Buzz Aldrin and Edgar Mitchell, have let it be known that aliens have visited Earth. I linked to their statements in an earlier blog, but the revelation by Aldrin this summer was incredible - not just for what he said about a monolith on a moon of Mars (Phoebes), but because he said it at 38 seconds into the video taken from C-SPAN, by 52 seconds someone rudely reached in front of the camera and pulled a book or notes from before his face, and he was off by 61 seconds. I don't have to go searching on youtube for answers. Our family has met several high ranking NASA officials who have told us that our government is in contact with Visiting Others. If they are, there are patents to be had that are worth a lot of money. LCOL Corso went there in his book THE DAY AFTER ROSWELL, but I would not take everything he writes as gospel. I don't think such visitors would have come from Mars, but they might use it as a base for operations in our solar system. If for nothing else, it's an entire world to mine that is supposed to be entirely uninhabited. But this is pure speculation.

A more serious possibility for disinformation is the need to terraform Mars to serve as a lifeboat or quarantine point for some impending disaster on Earth. I see no evidence to support claims that a world is headed for impact of Earth, but I do see how very fast viruses can spread around our planet. A few hundred years ago people were isolated in many parts of Earth, and rarely traveled from one continent to another. Sailing ships changed that, and plagues spread across the globe, essentially wiping out many indigenous peoples. What took months to transport then takes hour today. Someone at NASA or elsewhere in government has probably sat down, done the math on virus mutations rates, and figured out how long it will take the right killer virus to evolve and spread everywhere. Given that rate, and the decline in effectiveness of antibiotics in fighting bacteriological infections, it's only a matter of time. This is the best case for Mars exploration, terraforming, and populating. But to tell the public that we have misled them about Mars for disease-related issues is to risk enough fear to shut down airlines, and bring on economic chaos. The nature of chaos is such that we can not know for sure when the great plague will strike. But a wise government would plays its cards well, keep the known space program close to Earth for as long as it can, and use whatever technology that it could through black budgets to make Mars a place that could serve humanity - a very limited fraction of humanity - when the need arises. But hey, I'm just a kid who would like one of those tickets to Mars.

Rockinright

Dec 2, 12:28 pm

One question then...haven't other countries also sent probes to Mars that measured more or less the same data, and would have to of course collude with NASA in this scenario?

David Roffman

Dec 2 4:40 pm

rockinright wrote:

One question then...haven't other countries also sent probes to Mars that measured more or less the same data, and would have to of course collude with NASA in this scenario?

David Roffman responds: Not one other nation has every had a working probe on Mars, unless you count the 15 seconds that the Soviet Mars 3 lasted after it landed in 1971. However, perhaps in terms of international cooperation, the public fails to see the forest through the trees. Does it make any sense whatsoever that the U.S. would invest so much capital on the International Space Station, and then have access to it for so long only by way of Russian 2-man Soyuz capsules? We probably have access via black budget technology, but the people who might know about it would risk their careers or even their lives by telling us about it. These are very sensitive areas, but there are open source discussions out there worth studying. One of the more interesting "confessions" about how the system (which is international in scope) works was by Edgar Mitchell. Listen carefully to him at http://www.youtube.com/watch?v=RhNdxdve ... re=related. Go to 7:24 of the interview. The Kerrang talk show host asks..."going public with this - are you worried about your safety with this?" Mitchells's response: "I think those days are gone. It used to be a concern among people on the inside. I don't think they're knocking off anybody for that anymore or doing drastic things."

We have known three people (2 are now deceased) who were on the inside. Of the three, two suffered threats, and one endured much worse. But the message of all three was consistent with the Aldrin and Mitchell interviews. Sadly, I don't think that Dr. Zubrin was ever on the inside, but we mightl be using his ideas there now. Obviously, if our Governments (plural) have had on ongoing relationship with Visiting Others, it renders questions about how to get to Mars rather trivial, and it leaves our scientists at the mercy of whatever data is contrived and thrown at them. Like the old computer adage goes, garbage in, garbage out. What I am trying to prove about Martian atmospheric pressure almost seems crazy if it's just out of my head. But when you start out with serious reasons to believe that the data is hosed, it's not too hard to put it under the microscope and see what's a hoax and what is not.

Rockinwrite

Dec 2, 12:35 pm

Not to get too political, but Climategate is one thing - lots of people stand to benefit from the idea of having to totally change how we use energy, "green" technology, etc...

But this? Why does the need to terraform Mars mean they mislead about pressure? If it needs to be done it needs to be done whether 6mb or 100mb of atmosphere exists...not sure why this would make a difference. If they're secretly planning to terraform, I'm not sure how reporting incorrect atmospheric pressure changes that, unless perhaps it means Mars could harbor life already, and knowing that would create pressure against terraforming, but even that seems a stretch.

David Roffman

Dec 2, 9:27 pm

Rockinright wrote:

Why does the need to terraform Mars mean they mislead about pressure? If it needs to be done it needs to be done whether 6mb or 100mb of atmosphere exists...not sure why this would make a difference. If they're secretly planning to terraform, I'm not sure how reporting incorrect atmospheric pressure changes that, unless perhaps it means Mars could harbor life already, and knowing that would create pressure against terraforming, but even that seems a stretch.

Whoa, the first step is to figure out if Mars does indeed have higher pressure than claimed. If it does, that does not imply terraforming. However, in trying to learn if the problem with data is due to incompetence or disinformation, (only) one of several paths that disinformation might lead us to does relate to the terraforming question. And here, at this time, without proof of disinformation, we don't have a General Circulation Model to follow. We only have a Hollywood, SCIFI model. So, in the spirit of entertainment, I'll turn to one of my favorite, classical science fiction films entitled Soylent Green (http://video.google.com/videosearch?q=s ... 505&view=2). It deals with a theoretical future where there is a runaway greenhouse effect on Earth (not caused by the University of East Anglia), and with what the government would have to do to feed the starving masses.

What was great about the Soylent Green plot was how Detective Thorn, a New York City homicide investigator, put together facts from many disciplines to arrive at not only the motive behind a murder, but with how that murder led to an appalling truth about our food supply. The investigation of Martian pressure may turn out to be a bust, or it may lead to truths that are very uncomfortable for people in power. A Mars wth 6 mbar pressure, history shows, has a hard time competing for limited government funds. People reading this blog will still care about it, but most others don't think it's worth the money. However, a Mars that harbors life, as you suggest, is another matter. There are people on Earth that can breathe on top of Mount Everest where air pressure is about one third of what it is at sea level. So maybe that's around 338 mbar. Anything alive on Mars now has probably had the chance to evolve to operate in a lower pressure environment. I don't know if that means 338 mbar or 100 mbar, I just know that the weather we see on Mars does not match up well with common sense as to what we should be seeing at 6 mbar. And I know that a fast, public push for Mars would be a problem for planners who were privileged to have data (that required classification) supporting life (especially intelligent life) on Mars.

As for pressure against terraforming if there is life there, I'm not sure that this is the right way to approach the problem. The more famous UFO incidents early on (Roswell, 1947) etc. involve problems associated with military facilities here. When you consider the mind set of the Cold War, when the U.S. and Russia set off nuclear weapons on our own territories, and then had our own troops march through the radioactive test sites soon after detonation, a threat from off world could have provoked a hostile response by the U.S. and/or the Russians. In a world with tens of thousands of nuclear weapons on a trigger fuse, I doubt that military planners were worried about future Martian research. If I were a science fiction writer, I might pen a story about some of the failures of Mars probes (especially Soviet Mars probes) really being biological weapons that were sent there. Hey, we could even throw in some nukes that might explain the dust storms (and even some of the flares seen from Earth).

Some of the Cold War politicians undoubtedly were familiar with the tale by H.G. Wells where, in War of the Worlds, it is terrestrial bacteria that finally did away with the evil Martians. Dr. Zubrin wrote about bacteria being used to terraform Mars (p. 266 of THE CASE FOR MARS). You see the problem that President Obama has in formulating war policy in public with respect to Afghanistan. Just imagine how much harder it would be to do so when dealing with beings of uncertain origin and intent, and this overlooks the question of superior technology as suggested by UFOs. In short, the mere detection of conditions on Mars that would permit life there would probably be classified until we knew exactly how to deal with it should it actually prove to be from there. And, if we were in doubt about life on Mars, selection of the right bacteria to send there might not only help us to wipe out possible bad guys, but to prepare the way for us. But please, don't focus on these mind games too much. One step at at time - the focus for now must be on the pressure data, and whether for some reason, it was corrupted. http://davidaroffman.4t.com/photo5.html

Jumpboy11j

Dec2, 11:02 pm

When you start accusing the good people at NASA of purposely corrupting information and lying to the general public, I can't say you're in good company.

David Roffman

Dec3, 2:41 pm

jumpboy11j wrote:

When you start accusing the good people at NASA of purposely corrupting information and lying to the general public, I can't say you're in good company.

David Roffman responds: Are you accusing Senator Inhofe http://www.foxnews.com/search-results/m/27550383/climategate-probe.htm#q=climategate of Oklahoma as not being good company? He wants an investigation of Climate Gate. I just leaned that NASA is under threat of a lawsuit for the data that was corrupted here on Earth. Perhaps you want to write off our lunar astronauts, Aldrin and Mitchell, who probably risked their lives again to try top get the truth out. Maybe they are not good company for you, but they are welcome in our home anytime.

But let's be frank, ignoring everything I've heard off the record from three high NASA officials, nobody gets a free pass here, and that includes me. I'm putting my data out there, and my challenges to the legacy data are not under a pen name like you use, but under my real name, David A Roffman. Right now NASA is starting to sweat on their Global Warming data. That's a separate issue from the Mars pressure problem and the people who were involved with it, but if NASA does cook the books on an issue like global warming, then how far does that policy extend?

You seem to overlook the fact that I have repeatedly written that I have not proven disinformation, the deliberate distortion of data for political purposes. I only seem to have found enough reasons to question how NASA arrived at the low pressure figures for Mars; that the probes that landed on Mars were not designed to adequately measure a wide range of pressures, that they had serious problems or inability to measure wind speed, or to accommodate for rapid clogging of the tiny dust filter used for the Vaisala pressure sensor on Phoenix. Given that Phoenix was hit with 30 dust devils in 151 sols, this is not a trivial deficiency. It seems like only one person at this site, Midoshi, has made any kind of serious attempt to answer my growing list of concerns, and he has left 90% of my points unaddressed (points like just how much NASA Ames had to jack up wind speeds to lift dust at 10 mbars in a simulated Martian environment). The silence out there is starting to be deafening. I have a right to have each point addressed, not just the softballs that I toss out.

Midoshi is to be commended for giving me some terrific pointers and a few hard balls that I'll try to hit in a course next semester. My research is by no means even close to finished. In fact, I've got enough information now to start years of research. Hopefully the hard balls that I've thrown out will not keep NASA from giving me the opportunity to check their data further.

Let me finish by making this point clear. I have the greatest respect for the vast body of the NASA workforce, and for my professors who work closely with them. But you can have 5,000 scientists working to get the job done right, and one who has access to the data who can change its meaning entirely. You must be aware that astronauts have a separate channel that they are supposed to use to discuss information that is sensitive. I was watching the film THE RIGHT STUFF recently. When Alan Shepard was about to take off, he radioed the prayer, "Oh Lord, please don't let me F**K up!" "Say again," came the voice from Mission Control. Shepard, glad to have the chance to rephrase his remarks, replied,"Everything is A-OK." And that's what the public got to hear. Hopefully, I have not f**ked up in exposing the apparent weaknesses in the Martian pressure portrait presented by NASA. But I certainty don't think that everything is A-OK with Martian weather data, and I don't think it will be until we get the right weather suite on Mars with proper supervision of how the data gets from there back to the analysts on Earth.

Rockinright

Dec 3, 2:57 pm

Rockinright responds to the above e-mail:

Pursuing Climategate is NOT the same thing.

David Roffman

5:53 pm

David Roffman responds to the above e-mail:

You're correct, but like a lot of other information, it should not be overlooked. Politics (and religion) should not be allowed to distort scientific data. But it has happened throughout history, and I noticed when I attended the Mars Society Convention in Boulder last yearthe Vatican had a representative there. If nothing else, they are keeping a finger on the pulse of what is being said. I also notice that you have not addressed the bulk of the information covered in my Mars Report and in previous blogs. Why do you also overlook the Aldrin and Mitchell statements?